Cement-lined pipe.



PATENTED APR. 7, 1903;

J. T. LANGFORD. CEMENT LINED PIPE.

APYLIOATION FILED J'Q'NE 16, 1902..

' MODEL.

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UNITED STATES PATENT OFFICE.

JOHN T. LANeFoRp, F NEWTON, MASSACHUSETTS.

CEMENT-LlN EDPlPE.

SPECIFICATION forming part of Letters Patent No. 724,892, dated April '7, 1903.

Application filed June 16,1902. Serial No. 111,866. (Modeli) new and useful Improvements in Cement- Lined Pipes, of which the following is a specification.

This invention relates to improvements in cement-lined pipes particularly designed as conduits for water or electric wires, and it is carried out as follows, reference being had to the accompanying drawings, wherein- Figure 1 is a side elevation of my invention. Fig. 2 is a longitudinal section of the same, and Fig. 3 is a cross-section on the line 3 3 shown in Fig. 1.

Similar letters refer to similar parts wherever they occur onthe different parts of the drawings.

In the drawings, A represents a metal pipe, either cast, drawn, or riveted inthe usual manner. The interior of such pipe is provided with a suitable dried cement lining B.

The cement lining of metal pipes as usually made is liable to be porous and in such condition will absorb moisture conductive to electric currents, which is disadvantageous, particularly if the pipes are used as conductors for electric wires. 1 Such cement-lined pipes are usually not smooth on the interior of the lining, and if used as conduits for liquids are liable to become impregnated and coated with impurities contained in the wa ter or liquid, and if used for electric wires causing friction in drawing the wires through the pipes, and toobviate such objections I constructmy improved cement-lined pipe as follows The interior of the said cement lining-B is coated smoothly with Japan enamel paint or similar coating 0, which serves as a non-absorbent for liquids and moisture, thus of a lining of cement provided on its interior with a smooth coatingof japan, substantially as described.

2. A new article of manufacture comprising a metallic pipe provided with a lining of hydraulic cement, the interior of said lining and the exterior of the metallic pipe being' provided with a smooth coating of japan, substantially as described.

In testimony whereof I have affixed my signature in presence of two witnesses.

JOHN T. LANGFORD; Witnesses:

ALBAN ANDREN, ELIZABETH L. .RoBINsoN. 

